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    <title>Adding an Overlay to the Map</title>
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        <h1>Adding an Overlay to the Map</h1>
        <p>Display custom map tiles as an overlay</p>
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    <p>This example displays a movable map initially centered on the historical centre of <b>Berlin</b> (<i>52.515, °N, 13.405°E</i>) with an overlay of a historical map from 1789 on top of the base map. A public domain image was used as a source, and split it into individual map tiles. Additional tiles are only downloaded when the zoom level or location changes.</p>
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    <h2>Credits</h2>
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      <span>Wikimedia Commons Images</span><br/>
        The tile source is based on <a href="https://commons.wikimedia.org/wiki/File%3AMap_de_berlin_1789_%28georeferenced%29.jpg" target="_blank">an image of Berlin in 1789</a> from Wikimedia.<br/>
        Images provided by Wikimedia Commons are under the copyright of their owners.<br/>
        However, almost all <a href="https://commons.wikimedia.org/wiki/Commons:Reusing_content_outside_Wikimedia" target="_blank">content hosted on Wikimedia Commons</a> may be freely reused subject to certain restrictions.<br/>
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    <h3>Code</h3>
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        The example uses the <a target="_blank" rel="nofollow" href="http://developer.here.com/javascript-apis/documentation/v3/maps/topics_api_nlp/h-map-provider-imagetileprovider.html"><code>H.map.provider.ImageTileProvider</code></a> class for fetching our custom tiles. The <code>getUrl()</code> method constructs the URL of the tile for the specified column/row/zoom position. The result is displayed on the map as an additional layer using an instance of the <a target="_blank" rel="nofollow" href="http://developer.here.com/javascript-apis/documentation/v3/maps/topics_api_nlp/h-map-layer-layer.html"><code>H.map.layer.TileLayer</code></a> class which has been created by passing in the image tile provider object.
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